In the first part of this week's work, you will learn about conditional expectation as an operator and then the conditional expectation function.
Sometimes these concepts can be a little difficult to keep straight—as we will use them in this class:
- Functions map inputs onto outputs. The inputs and outputs could be any sets, but the domain is often a sample space or the real numbers.
- We use the word operator instead of function when the inputs are random variables (which are functions) and the outputs are real numbers. Each random variable is mapped to a single real number.